GimmBO: Interactive Generative Image Model Merging via Bayesian Optimization

Fig. 1. Given a prompt, default image generation may appear reasonable yet fail to match a user's creative intent (left). GimmBO enables users to explore weighted combinations of customization adapters (30 in this example) through preference feedback, producing an image that better reflects the desired style (right, corresponding adapter coefficients below). Readers are encouraged to zoom in on images for finer details throughout the paper.

Fine-tuning-based adaptation is widely used to customize diffusion-based image generation, leading to large collections of community-created adapters that capture diverse subjects and styles. Adapters derived from the same base model can be merged linearly, enabling the synthesis of new visual results within a vast and continuous design space. To explore this space, current workflows rely on manual slider-based tuning, an approach that scales poorly and makes merging coefficient selection difficult, even when the candidate set is limited to 20-30 adapters. We propose GimmBO to support interactive exploration of adapter merging for image generation through Preferential Bayesian Optimization (PBO). Motivated by observations from real-world usage, including sparsity and constrained coefficient ranges, we introduce a two-stage BO backend that improves sampling efficiency and convergence in high-dimensional spaces. We evaluate our approach with simulated users and a user study, demonstrating improved convergence, high success rates, and consistent gains over BO and line-search baselines, and further show the flexibility of the framework through several extensions.